1. Field of the Invention
The present invention generally relates to the storing of data on magnetic tape media and, more particularly, to tape heads for writing data to and reading data from magnetic tape media.
2. Relevant Background
The market for mass storage devices is growing at an ever increasing rate with the sales of high-performance computers penetrating numerous industries ranging from financial institutions to oil exploration companies. The processing power of these high-performance systems, and the data they generate, are increasing faster than the ability of storage devices to keep pace. The problem of data storage and rapid retrieval is particularly pronounced in computational-intensive applications which create huge amounts of data that need to be accessed in seconds rather than minutes, hours or even days.
Magnetic disks remain the preferred media for direct access to frequently used files because of their fast access times. However, because of their high cost per-unit of storage and limited capacity, magnetic disk recorders are prohibitively expensive and therefore impractical for large-scale data storage. With the advances in magnetic tape technology, tape based systems remain the preferred choice for mass data storage. In addition to cost, magnetic tape exceeds the storage density of almost any other medium, at least from a volumetric standpoint, because tape is a much thinner medium than, for example, magnetic disks, and tape can be tightly packed.
Magnetic tape (e.g., recording tape) is a magnetic recording medium made of a thin magnetizable coating on a long, narrow strip of plastic which is typically stored in the form of a spool on a cartridge or cassette. Typically, multiple, parallel data tracks may be written to and/or read data from the tape in one of a number of manners. In “linear” or “longitudinal” reading or recording, data is read or recorded by one or more tape heads (e.g., each including one or more tape head modules that each have a plurality of read or write elements such as 16, 32, etc.) of a tape drive or recording device by moving the tape relative to the tape head(s) from a starting point on the first track of the tape and moving linearly down the tape along the first track or along a first path. Once the physical end of the tape (EOT) is reached, the tape is rewound to the beginning of the tape (BOT) at which point each tape head begins reading or recording linearly down the tape along the second track or along a second path. Variations of the linear method include “serpentine” and “spiral in” reading and recording. One or more tracks written at the same time along the tape length may be referred to as a “wrap.” In this regard, a new wrap begins each time the head assembly begins reading or writing in the forward or reverse directions. Often, magnetic tape is pre-formatted with a plurality of guards (i.e., strips of the tape on which user data cannot be written) running either perpendicular to the tape length (to separate the tape into a number of sections or segments) or along the tape length (to separate the tape into a number of servo portions or data bands on which independent read/write heads can operate).